Freezing, shortages among global vaccine challenges

A special supplement to the journal Vaccine published yesterday aims to measure the biggest challenges to global vaccine campaigns today, noting that vaccine stockouts—or complete unavailability of vaccines—occur at least monthly, while 19% to 38% of vaccines worldwide are subjected to improper refrigeration practices.

The 29-article issue was coordinated by the global health nonprofit PATH, with guest editors from the Bill & Melinda Gates Foundation, UNICEF, and the Johns Hopkins Bloomberg School of Public Health.

Vaccine freezing common

Benjamin Schreiber, a senior health advisor with UNICEF and one of the editors of the supplement, explained that outmoded delivery systems could compromise the efficacy of vaccines.

“Often a supply arrives in a capital city and has to travel hundreds of miles before it gets to the correct clinic or health center,” Schreiber said in an interview. “We know a vaccine has to be kept stable at 2 to 8 degrees [Celsius, or 36°F to 46°F], but our data show that’s not happening at least 20% of the time.”

As part of the special issue, Schreiber co-authored a literature review on vaccine temperatures that looked at 45 studies on vaccine freezing in the supply chain. About half of all vaccines procured by UNICEF are “freeze sensitive,” meaning they are subject to damage if exposed to improper temperatures.